Synchronizing-clock.



1. w. BRYCE. SYNCHRONIZING CLOCK.

APPLICATION FILED SEPT- 24. 191B.

Patented July 22, 1919.

2 SHEETS-SHEET I J. W. BRYCE.

SYNCHBONIZING CLOCK.

APPLICATION FILED SEPT. 24. I918.

Patented July 22, 1919.

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UNITED STATES PATENT OFFICE.

JAMES W. BRYCE, OF BINGHAMTON, NEW YORK, ASSIGNOR T0 INTERNATIONAL TIMERECORDING COMPANY OF NEW YORK, A CORPORATION OF NEW YORK.

SYNCHRONIZING-CLOCK.

Specification of Letters Patent.

Patented July 22, 1919.

Application filed September 24, 1918. Serial No. 255,417.

T 0 all whom it may concern:

Be it known that I, JAMES W. BRYCE, a citizen of the United States,residing at Binghamton, in the county of Broome and State of New York,have invented certain new and useful Improvements inSynchronizing-Clocks, of which the following is a full, clear, and exactdescription.

In a prior application filed by me, Serial No. 235,813, filed May 21,1918, I have shown and described a synchronizing clock system in whichthere are combined a master-clock and one or more secondary clocks underthe control of the former. One of the more prominent features of thissystem consists in the means employed for maintaining the secondaryclock or clocks in approximately perfect synchronism with the masterclock, at least during the working hours when the clocks are in use forthe control of such means as time recording devices, between which, oreven during such periods. there may occur interruptions in the supply ofthe more powerful currents required for the operation of the system. Theprimary object of the invention was to dispense with a continuouslydependable source of current, such as would be afiorded by a storagebattery or the like.

In the system in question, each secondary clock operated circuitcontrollers by means of which the said clocks were brought at certaintimes and for definite periods into such operative relations to the linecircuit or a line circuit running from the master clock, that by currenttransmitted over such circuit for definite periods by the master clock,the secondary clocks out of synchronism would be retarded or acceleratedas the case might be until by their retardation or advance they werebrought into exact synchronism with the master clock, when thesynchronizing circuits would be interrupted either by the master orsecondary clocks and the latter would thereafter run without controluntil such time as these circuits might be reestablished.

The invention, subject of this application is an improvement on suchsystems, and has to do solely with the means for retarding or foraccelerating the secondary clocks to bring them, provided they be toofast or too slow, into exact synchronism with the mast'ar clock.

Generally stated this improvement conslsts in means for varying thelength of the pendulum of a secondary clock if such device be used asits regulator, or the length of the hair spring, if such be the meansemployed for that purpose, at certain definite perlods, provided theclock be either too fast or too slow. For this purpose each secondaryclock is provided with two circuit controllers which by the movements ofsuch clocks are operated during certain predetermined periods to close acircuit from the master clock over which in certain fixed relation tocorrect time, current is transmitted. If one of the circuit controllersin a secondary clock, therefore, closes this circuit at the instant whenan impulse period established by the master clock begins or ends, thenthe master and that secondary clock are in synchronism and nothingoccurs. But should this secondary clock circuit controller close thiscircuit for a period overlapping that of a current transmitting period,there will be a certain flow of current through one or the other of suchcircuit controllers which will be utilized to increase or decrease thelength of the pendulum or hair spring, and thereby cause the secondaryclock to slow down or speed up until by one or more such operations itis brought into exact synchronism with the master clock.

In illustrating this invention I have shown diagrammatically merely suchparts of the master and secondary clocks and circuits as are directlyinvolved in the carrying out of the improvement, as all else is now wellknown as a result of my previous work in this connection.

Figure 1 is a side view of a pendulum clock with means attached theretofor varying the length of the pendulum.

Fig. 2 is an enlarged detail View in elevation of such means.

Fig. 3 is a section view of the ratchet mechanism of the same.

Fig. 4 is a sectional view of the same device.

Fig. 5 is a diagrammatic view showing the relation of the master to asecondary clock, an

Fig. 6 is a view of a modification of Fig. 2.

A designates the frame of a pendulum clock of the kind contemplated forthe purpose of this invention. B the works thereof closely embraces themetal strip D.

This arm extends from a threaded sleeve F on a correspondingly threadedspindle G,

the-sleeve being held against rotation by an arm .H with an eye thereinthrough which passes a smooth fixed vertical rod K. The spindle Gcarries two ratchets I and J w1th teeth oppositely set, and with theseratchets engage the pawls L connected to the armatures M of twoelectro-magnets N, O. The ratchets are so designed that withoutmterference they will turn the screw G in opposite directions.

Magnet N is included in a branch of a circuit from the master clock,which in addition to the devices connected therewith in that; clock,contains a circuit controller P normally open but adapted to be closedby the raised portion of the periphery of a disk Q rotated by thesecondary clock mechanlsm.

Magnet 0 is included in a branch of the same or a similar circuit whichcontains a circuit controller R, held normally open by a disk S, butallowed'to close when one of its members reaches a cut away portion inthe periphery of said disk.

At predetermined intervals of definite length, a current is transmittedfrom the master clock over the line T. If this current is receivedthrough the circuit controller P, it is broken up into impulses by thecontacts U, rotated by the secondary clock, and the magnet N is operatedand caused to move the ratchet wheel I step by step by such impulses andlowers the arm E to shorten the pendulum. On the contrary, if theimpulses are received by magnet O, the pendulum is lengthened, as thespindle G is turned in the opposite direction.

The operation in detail may therefore be described as follows: Let it beassumed that from fifteen minutes of the hour until the hour, thisperiod being selected merely for purposes. of illustration, the -masterclock sends a current into the line T by means to be hereinafterdescribed. Let it also be as sumed that at the hour, according to thehands of the secondary clock, the contacts R- slip into the cut awayportion of the disk S. It is manifest, therefore, that if the sec-'ondary clock /is exactly on time, the circuit controller R will beclosed at the instant that the current flow from the master clockceases, so that nothing will happen.

Should the secondary clock, however, be fast, the contacts will dropinto the cut away portion before thehour, or while the current is comingfrom the master clock. This current broken into impulses, then, untilthe master clock stops sending current, will pass through the magnet Oand raise the sleeve F on the pendulum giving to the clock a slowerrate.

A similar but opposite effect is produced by the circuit controller P.If the clock is slow, the raised portion of the disk which should leavethe contacts at exactly fifteen minutes of the hour will not permitthese contacts to open at exactly that time, but will maintainthemclosed while current is coming from the master clock and this results inshortening the pendulum by magnet N and giving to the clock a fasterrate. V

In practical operation, since the adjustment of the above describeddevices occurs once each hour, the departure of any secondary lock fromapproximate synchronism is so slight that but few current impulses willpass through eithermagnet N or O. In case of protracted failureof'current and the clocks get much out of synchronism, they are soonbrought back into unison, 1f not entirely by one, certainly by a veryfew adjusting operations.

Instead of varying the length of the pendulum the same result may beaccomplished by varying the length of'a hair spring. In Fig. 6 this isindicated where a lever V is raised or lowered by an arm W on theprolongation of the spindle G and this operates to vary the efle'ctivelength of a hair spring X. 1

It will be understood that no means for winding the secondary clocks or.performgrammatically only, as consisting'of a disk Y with conductingsegments on which bear brushes Z, that for a definite period, the diskbeing driven by the master clock, maintain either a high or low point ofa ratchet Z opposite one of a pair of contacts X in the line circuit.

I am aware that in the prior art provision has heretofore been made foradvancing and retarding, using the latter termin a broad sense, thehands of a clock at any desired interval of time for maintaining suchclock in synchronism with a master clock, but no means have beenheretofore proposed to my knowledge for providing trio circuit, a masterclock and one or more secondary clocks controlled thereby, the

combination in each secondary or controlled clock of means for varyingthe length of the pendulum, circuit controllers adapted to be closed forgiving periods of substantial duration by and in definite relation tothe time as indicated by the hands of the controlled clock, means in themaster clock for connecting to the circuit including said controllers asource of current for definite periods of predetermined durationwhereby, when the periods of closure in the secondary clock overlap thatof the master clock, current will be directed through one or the otherof said circuit controllers to the means for lengthening or to the meansfor shortening the pendulum according to whether the secondary clock betoo fast or too slow, and operate said means during the iantire intervalby which said periods over- 2. In a clock system comprising an electriccircuit, a master clock and one or more secondary clocks controlledthereby, the combination in each controlled clock of electromagneticratchet and pawl devices, one for lengthening, and the other forshortening the pendulum, circuit controllers adapted to be closed forgiven periods of substantial duration by and in definite relation tothetime as indicated by the hands of the controlled clock, and means inthe master clock for connecting to the circuit including the saidcontrollers a source of current impulses for definite periods ofpredetermined duration, whereby, when the periods of closure in thesecondary clock overlap that of the master clock, impulses of currentwill be directed through one or the other of said circuit controllers tothe ratchet device for lengthening, or to that for shortening thependulum according to whether the secondary clock be too fast or tooslow, and effect the operation of said devices during the entireinterval by which said periods overlap.

3-. The combination with a secondary clock of a spindle which by itsrotation in opposite directions lengthens or shortens the pendulum,ratchets and pawls and electromagnets for operating said pawls andthereby turning the spindle in opposite directions, circuit controllersoperated by the clock mechanism and adapted to be closed thereby forgiven periods, circuit connections and a device for developing impulsesof current between the said controllers and the electro-magnets, wherebycurrent when received through a closed controller will be transmitted asimpulses therefrom to the magnet connected therewith.

In testimony whereof I hereunto afiix my signature.

JAMES W. BRYCE.

